JP2006513670A - Data communication method through human body, data communication system through human body, and sensing device used therefor - Google Patents

Abstract

The present invention provides a data communication method through a human body, a data communication system through a human body, and a sensing device used therefor.
The present invention transmits information through a human body to a receiver external to the human body using a human body as a conductor, a signal as a voltage polarity, and using low frequency, low current and voltage polarity. As a result, it is possible to provide a communication method through the human body and a communication system through the human body that are harmless to the human body, consume less power, and have excellent reception sensitivity. In addition, the present invention is a low-cost, low-cost, all-circuit integrated circuit in a CMOS image sensor that does not require a wireless transmitter and antenna as a sensing device used in a communication method through a human body and a communication system through a human body. A compact capsule endoscope is also provided.

Description

  The present invention relates to a method and system in which a sensing device inserted into a human body for the purpose of collecting various medical information transmits data to the outside of the human body, and more particularly, a current generated from the sensing device is a human body. The present invention relates to a data communication method through a human body capable of transmitting data to the outside of the human body by flowing as a conductor, a data communication system through the human body, and a sensing device used for these.

  Various sensing devices that collect medical information inside the human body have been developed and used. In addition to such information collection technology, technology that transmits the collected information to the outside of the human body is also very important. .

  As a general data transmission method, there is a communication cable method applied to an endoscope developed for the purpose of observing the internal state of the gastrointestinal tract. In this communication cable system, a cable made of a conducting wire or an optical fiber is inserted into the human body mainly through the patient's throat. Such a communication cable system has the advantages of high reliability and excellent quality of data collected inside the human body. However, there has been a problem of severe distress to patients undergoing endoscopic procedures.

  In order to solve such problems, Israel's Given Imaging has recently developed a capsule endoscope “M2A”. When the patient swallows the tablet like a tablet, the capsule endoscope sends video (video) data inside the human body captured by the camera of the endoscope to an external receiver. Can be played on the monitor.

  However, since the capsule endoscope employs a radio wave system as a signal transmission system, the power consumption is large and the operation time is short. In addition, the reception sensitivity deteriorates due to various radio wave interference outside the human body. Furthermore, since a modulation circuit that modulates a video signal into a high-frequency signal and a wireless transmitter such as an antenna for transmitting the signal must be provided, the size increases and the production cost increases. Furthermore, there is a problem that the use of high frequency may cause harmful effects on the human body.

  Accordingly, the present invention has been made in view of such a conventional problem, and allows a current generated by a sensing device inserted into the human body to flow using the human body as a conductor and transmit data to the outside of the human body. It is an object of the present invention to provide a data communication method through a human body and a data communication system through a human body.

  Another object of the present invention is to provide a sensing device including a transmission electrode that generates a current inside the human body and transmits data to the outside of the human body by flowing the current through the human body.

  In order to achieve such an object, a data communication method through a human body according to the present invention is a data communication method through a human body that transmits a signal to the outside of the human body from a sensing device input into the human body. A step of generating a potential difference between the transmission electrodes installed on the surface of the sensing device, and a current is supplied to the inside of the human body from the transmission electrode having a relatively high potential, and after flowing through the surface of the human body, The step of sinking the current flowing into the human body again to the transmitting electrode having a relatively low potential, and the current flowing through the surface of the human body induces a voltage between the receiving electrodes attached to the surface of the human body. And a step of performing.

  In addition, the data communication system through the human body according to the present invention includes a sensing device including a transmission electrode that is inserted into the human body to generate a potential difference, and receives current generated by the potential difference that is attached to the surface of the human body through the human body. And a receiver.

  A sensing device according to the present invention includes an illumination element that irradiates the inside of a human body, a lens that focuses light incident from the inside of the human body, and a CMOS image sensor that generates an electrical signal from the light focused by the lens. And a housing for housing the illumination element, the lens and the CMOS image sensor, and a transmission electrode installed on a surface of the housing and applied with the electrical signal.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating an embodiment for explaining a data communication method through a human body and a data communication system through a human body according to the present invention. As shown in FIG. 1, the sensing device 10 located inside the human body 1 (for example, digestive organ) transmits information inside the human body to a receiver 20 installed on the surface of the human body through the human body 2.

  In the data communication system through the human body according to the present invention, a data communication method through the human body for transmitting a signal from the sensing device 10 inside the human body 1 to the receiver 20 outside the human body will be described with reference to FIG. I will explain it. Various types of information collected by the sensing device 10 (for example, images inside the human body, PH, temperature, electrical impedance, etc.) are converted into electrical signals by a signal processing circuit inside the sensing device, and then the signal processing circuit Applied to the transmission electrode 11 through the output line, a potential difference is generated between the two transmission electrodes 11. This is because the transmission electrode 11 is in contact with the inside 1 of the human body (that is, the transmission electrode is electrically connected to the human body by body fluid in the digestive tract), and between the two transmission electrodes 11. This is because the current 3 flows through the human body 2 due to the potential difference. The current 3 flows from the transmission electrode having a relatively high potential, flows through the surface of the human body 2, returns to the inside 1 of the human body again, and is sunk by the transmission electrode having a relatively low potential. At this time, the current flowing on the surface of the human body induces a voltage between the two receiving electrodes 21, so that the signal transmitted from the sensing device 10 located inside the human body 1 can be detected by the receiver 20 outside the human body. It becomes like this. The receiver 20 processes the received signal and restores it to a video signal, which is displayed on a monitor in real time or stored in a memory.

  FIG. 2 shows several embodiments of the transmitting electrode 11 placed on the surface of the sensing device 10 used in the data communication system through the human body according to the present invention. As will be described later, on the surface of the sensing device 10, two metal plates, that is, transmission electrodes respectively connected to output lines of a signal processing circuit provided in the sensing device are formed.

  If the two transmission electrodes are electrically isolated and are sufficiently far apart from each other, the transmission electrodes can be formed at any location on the surface of the sensing device. Moreover, in order to always make it easy to contact a human body, it is preferable to form in the shape which covers a sensing device, ie, a three-dimensional curve shape.

  In FIG. 2, (a) shows the structure of the transmission electrode of the sensing device used in FIG. 1, and the transmission electrode includes a first electrode and a second electrode that surround both ends of the sensing device, respectively. Yes. The transmission electrode in (b) includes a first electrode that surrounds one end of the sensing device and a second electrode that covers the other end of the sensing device in a strip shape. The transmission electrode in (c) includes a first electrode and a second electrode that respectively cover both ends of the sensing device in a band shape. In addition, the transmission electrode in (d) includes a first electrode and a second electrode that are formed symmetrically about the major axis of the sensing device.

  Since the transmitting electrode is exposed to the inside of the human body, it must be a metal that has excellent corrosion resistance and is harmless to the human body so that it can withstand reactive substances such as digestive fluid. In one embodiment of the present invention, SUS316L or gold is used as a metal that is excellent in corrosion resistance and harmless to the human body. Further, in order to electrically insulate the transmission electrode formed on the surface of the sensing device, the surface of the sensing device must be made of an insulator that is harmless to the human body and does not conduct electricity. As an insulator that is harmless to the human body, a plastic-based peak, polyethylene, or polypropylene can be used. In order to further improve the harmlessness to the human body, parylene can be coated on the surface of the sensing device made of peak, polyethylene or polypropylene.

  FIG. 3 is a cross-sectional view showing the internal structure of a capsule endoscope as an embodiment of a sensing device used in a data communication system through a human body according to the present invention. The capsule endoscope shown in FIG. 3 has a diameter of about 10 mm and a length of about 20 mm. One end of the housing forming the outer shape of the capsule endoscope is formed by a dome-shaped light receiving window 17, and the other end is formed by a rectangular housing 18. Therefore, it has a bullet shape as a whole.

  The light receiving window 17 of the capsule endoscope is a portion through which light passes, and is formed of a material that allows light to pass through harmlessly to the human body. The storage body 18 is a part formed by including some elements to be described later, and is made of an insulator that is harmless to the human body. The light receiving window 17 and the container 18 are sealed. For example, digestive organ mucus or the like penetrates into the capsule endoscope, or a substance in the capsule endoscope leaks into the human body. There is no such thing.

  As shown in FIG. 3, the capsule endoscope has an outer shape of a housing including a light receiving window 17 and a storage body 18. The housing 18 includes the illumination element 12, the lens 13, the CMOS image sensor 14, the battery 15, and the transmission electrode 11 formed on the surface of the housing 18 so as to be electrically insulated.

  A lens 13 is disposed behind the light receiving window 17, and a CMOS image sensor 14 in which various circuits are integrated is disposed behind the lens 13. The distance between the lens 13 and the CMOS image sensor 14 is adjusted so that light incident through the light receiving window 17 is focused on the surface of the CMOS image sensor 14. Between the lens 13 and the CMOS image sensor 14, a plurality of illumination elements 12 are arranged in a donut-like arrangement. In one embodiment of the present invention, four LEDs are used as the lighting element 12. A non-reflective coating is applied to the inner and outer surfaces of the light receiving window 17 so that the light emitted from the illumination element 12 can smoothly pass through the light receiving window 17 and illuminate the object. A battery 15 for supplying power is disposed behind the CMOS image sensor 14. In one embodiment of the present invention, a silver oxide battery having a flat discharge voltage and less harm to the human body is used as the battery 15.

  The internal operation of the capsule endoscope will be briefly described below. While the illumination element 12 irradiates light, the CMOS image sensor 14 captures (captures) an image of the object through the lens 13, processes the captured image signal by various internal circuits, and then performs the processing. The applied signal is applied to the transmission electrodes respectively connected to the two output lines 16. As a result, as described above, the reception electrode outside the human body can sense the signal using the human body as a conductor.

  FIG. 4 is a circuit configuration diagram of the CMOS image sensor 14 for explaining the operation principle of the capsule endoscope in more detail.

  As shown in FIG. 4, the CMOS image sensor 14 includes a pixel array 100 that captures and stores a video signal, a read circuit 110 that sequentially extracts a signal of each pixel, and a code that encodes an output signal of the read circuit 110. Circuit 120, a switching circuit 130 that transmits the signal encoded by the encoding circuit 120 to two output lines, and a current limiting circuit 140 that adjusts the current value so that a current that is harmful to the human body does not flow. And a control circuit 150 that controls the signal processing and the operation of the lighting element 12, and an oscillation circuit 160 that determines the operating frequency.

  In one embodiment of the present invention, the pixel array 100 has 320 × 240 pixels and can capture and store a high resolution video signal. The stored video signal is sequentially processed by the read circuit 110 frame by frame per second. Therefore, a memory that is disadvantageous in terms of cost and size can be eliminated. In addition, the control circuit 150 determines the brightness inside the human body from the brightness of the light incident on the pixel array 100, changes the illumination element 12 between 5 and 200 msec, and controls its operation. The video signal in the meantime is captured by the pixel array 100. Thereby, each video frame is captured instantaneously and the brightness is improved. As the encoding method, a PSK method that is simple and has noise resistance is adopted.

  When the signal transmitted from the encoding circuit 120 is “1”, the switching circuit 130 applies a “+” voltage to the first output line 16 a to ground the second output line 16 b, and from the encoding circuit 120. If the transmitted signal is “0”, the first output line 16a is grounded and a “+” voltage is applied to the second output line 16b. Thus, noise resistance can be further enhanced by transmitting the signal not by the magnitude of the voltage but by the polarity of the voltage.

  The current limiting circuit 140 serves to prevent a current of 5 mA or more from flowing through the human body. In one embodiment of the present invention, the current limiting circuit 140 is realized by connecting resistors in series to the two output lines 16 of the switching circuit 130. That is, when the power supply voltage is 3V, if a current limiting circuit is configured by connecting 300Ω resistors in series to the two output lines, the resistance to the human body is very small. The flowing current does not exceed 5 mA. Furthermore, a capacitor is connected to each resistor in parallel to remove a high-frequency component of a signal transmitted to the human body and to achieve electrical matching with the human body, so that even better signal transmission is performed.

  The signal that has passed through the current limiting circuit 140 is finally applied to the two transmission electrodes 11 and transmitted to the outside through the human body. In the existing radio wave communication system, a high frequency signal of several hundred MHz is required. However, in the present invention, the video signal captured by the capsule endoscope is transmitted to the outside of the human body even by a low frequency signal of 10 MHz. be able to.

  As described above, the present invention is not a high-frequency radio system through an antenna, but communicates with a human body as a conductor at a low frequency and a low current, so that it is harmless to the human body and can reduce power consumption. In addition to reducing signal attenuation and not receiving radio wave interference outside the human body, the signal is transmitted with the polarity of the voltage, so that it is more resistant to noise and has an excellent reception sensitivity.

  In addition, the sensing device according to the present invention does not require a wireless transmitter and an antenna, but also sequentially processes video signals over time, so that a separate memory is not required, and the capsule type is small and inexpensive. There is an effect that an endoscope can be provided.

The figure which showed one Embodiment for demonstrating the data communication method through the human body which concerns on one Embodiment of this invention. 1 is a perspective view illustrating several embodiments of transmission electrodes installed on a surface of a sensing device used in a data communication system through a human body according to an embodiment of the present invention. 1 is a cross-sectional view of a sensing device used in a data communication system through a human body according to an embodiment of the present invention. The circuit block diagram which showed the inside of the CMOS image sensor of a sensing apparatus.

Claims (42)

In a data communication method through a human body for transmitting a signal to the outside of the human body from a sensing device thrown inside the human body,
Generating a potential difference between transmission electrodes installed on the surface of the sensing device;
Supplying a current from a transmitting electrode having a relatively high potential to the inside of the human body, passing a current returning to the inside of the human body through the surface of the human body, and sinking the transmitting electrode having a relatively low potential to the sinking electrode When,
Inducing a voltage between the receiving electrodes attached to the surface of the human body by a current flowing on the surface of the human body;
A data communication method through the human body, characterized by comprising:   The method according to claim 1, wherein the potential difference is generated by applying an electrical signal in the sensing device to the transmission electrode. A sensing device including a transmission electrode that is inserted into a human body to generate a potential difference;
A receiver that is mounted on the surface of the human body and receives the current generated by the potential difference through the human body;
A data communication system through the human body, characterized by comprising:   4. The data communication system through a human body according to claim 3, wherein the transmission electrode is electrically insulated from the surface of the sensing device.   The data communication system through a human body according to claim 3, wherein the transmission electrode is electrically connected to an internal circuit of the sensing device, and an electric signal generated from the internal circuit is applied.   5. The data communication system through a human body according to claim 4, wherein the transmission electrode is formed three-dimensionally.   The data communication system through a human body according to claim 6, wherein the transmission electrode includes a first electrode and a second electrode surrounding both ends of the sensing device.   The data communication system through a human body according to claim 6, wherein the transmission electrode includes a first electrode surrounding one end of the sensing device and a second electrode covering the other end in a band shape.   The data communication system through a human body according to claim 6, wherein the transmission electrode includes a first electrode and a second electrode that respectively cover both ends of the sensing device in a band shape.   The data communication system through a human body according to claim 6, wherein the transmission electrode includes a first electrode and a second electrode formed symmetrically about a major axis of the sensing device.   The data communication system through a human body according to claim 3, wherein an insulator for insulating a transmission electrode on a surface of the sensing device is formed of any one of peak, polyethylene and polypropylene.   The data communication system through a human body according to claim 11, wherein an insulator for insulating a transmission electrode on a surface of the sensing device is coated with parylene.   4. The data communication system through a human body according to claim 3, wherein the transmission electrode is formed of a conductive material harmless to the human body.   The data communication system through a human body according to claim 13, wherein the conductive material is SUS316L or gold. In a capsule endoscope thrown into the human body,
A lighting element that illuminates the interior of the human body;
A lens that focuses light incident from inside the human body;
A CMOS image sensor that generates an electrical signal from the light focused by the lens;
A housing for housing the illumination element, the lens and the CMOS image sensor;
A transmitting electrode installed on the surface of the housing and applied with the electrical signal;
A capsule endoscope comprising:   16. The capsule endoscope according to claim 15, wherein the transmission electrode is connected to an output line of the CMOS image sensor and is electrically insulated from the surface of the housing.   The capsule endoscope according to claim 16, wherein the transmission electrode is formed three-dimensionally.   The capsule endoscope according to claim 17, wherein the transmission electrode includes a first electrode and a second electrode surrounding both ends of the housing.   The capsule endoscope according to claim 17, wherein the transmission electrode includes a first electrode surrounding one end of the housing and a second electrode covering the other end in a band shape.   18. The capsule endoscope according to claim 17, wherein the transmission electrode includes a first electrode and a second electrode that respectively cover both ends of the housing in a band shape.   18. The capsule endoscope according to claim 17, wherein the transmission electrode includes a first electrode and a second electrode that are formed symmetrically about a major axis of the housing.   The capsule endoscope according to claim 15, wherein a surface of the housing is formed of any one of peak, polyethylene, and polypropylene.   The capsule endoscope according to claim 22, wherein a surface of the housing is coated with parylene.   The capsule endoscope according to claim 15, wherein the transmission electrode is formed of a conductive material harmless to a human body.   The capsule endoscope according to claim 24, wherein the conductive material is SUS316L or gold.   The capsule endoscope according to claim 15, wherein the front of the housing is formed of a dome-shaped light receiving window, and the rear of the housing is formed of a rectangular housing.   27. The capsule endoscope according to claim 26, wherein the light receiving window is made of a material that is harmless to a human body and allows light to pass therethrough.   27. The capsule endoscope according to claim 26, wherein a non-reflective coating is applied to an inner surface and an outer surface of the light receiving window.   The capsule endoscope according to claim 15, wherein the illumination element is an LED.   30. The capsule endoscope according to claim 29, wherein the operation time of the LED is variable between 5 ms and 200 ms. The CMOS image sensor is
A pixel array for converting a video signal into an electrical signal and storing the electrical signal;
A lead circuit for sequentially extracting electrical signals of the pixel array;
An encoding circuit for encoding the output signal of the read circuit;
A switching circuit that changes the polarity of the output line according to the encoded signal;
A current limiting circuit that limits the flow of current above a predetermined value;
A control circuit for controlling the operation of the illumination element and the operation of the CMOS image sensor;
An oscillation circuit for generating a pulse;
The capsule endoscope according to claim 15, comprising:   32. The capsule endoscope according to claim 31, wherein the pixel array converts an image signal into an electric signal and stores the electric signal while the illumination element is irradiating.   The capsule endoscope according to claim 31, wherein the lead circuit sequentially extracts and processes the electrical signals while the illumination element is turned off.   32. The capsule endoscope according to claim 31, wherein the encoding circuit executes PSK encoding.   The switching circuit causes a current to flow from the first electrode to the second electrode when the encoded signal is “1”, and from the second electrode to the second when the encoded signal is “0”. 32. The capsule endoscope according to claim 31, wherein the polarity of the output line is changed by passing a current through one electrode.   32. The capsule endoscope according to claim 31, wherein the current limiting circuit maintains the current at 5 mA or less.   32. The capsule endoscope according to claim 31, wherein the current limiting circuit is configured by connecting a resistor in series to each output line of the switching circuit.   38. The capsule endoscope according to claim 37, wherein the current limiting circuit further includes a capacitor connected in parallel to each of the resistors. In a data communication method through a human body for transmitting a signal from the capsule endoscope thrown into the human body to the outside of the human body,
Generating a potential difference between transmission electrodes installed on the surface of the capsule endoscope;
After a current is supplied from the transmitting electrode having a relatively high potential to the inside of the human body and flows through the surface of the human body, the current flowing into the human body again is sinked to the transmitting electrode having a relatively low potential. And the stage of
Inducing a voltage between the receiving electrodes attached to the surface of the human body by a current flowing on the surface of the human body;
A data communication method through the human body, characterized by comprising:   When the transmission signal is “1” of the digital signal, the capsule endoscope passes a current from one electrode of the transmission electrode to the other electrode, and when the transmission signal is “0” of the digital signal, The data communication method through a human body according to claim 39, wherein the polarity of the transmission electrode is changed by passing a current from the other electrode to the one electrode.   The method of claim 39, wherein the magnitude of the current is limited by a resistance connected in series to each of the transmission electrodes.   The method of data communication through a human body according to claim 41, wherein a capacitor is connected in parallel to each of the resistors.

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